Suction filter for a compressor

ABSTRACT

A suction fitting for a compressor can include screens, filters, and direction control louvers to both filter out particulates and direct higher mass liquid refrigerant downward away from the inlet to the compression chamber. Alternatively, a mesh filter can be place over the opening(s) to the suction plenum to prevent debris and contaminants from entering the suction plenum.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/756,696, filed Jan. 25, 2013, entitled SUCTION FITTING FOR A COMPRESSOR, which Application is incorporated by reference herein in its entirety.

BACKGROUND

The application generally relates to suction fittings and filters for a compressor.

Aftermarket compressors (compressors installed into systems to replace a failed compressor) typically fail at a rate 3 to 4 times higher than original equipment manufacturer (OEM) initial installations. The high failure rate can be due to a variety of factors that can be present or occur in field installations. Some of the factors contributing to a high failure rate can include the presence of acids in the system from a motor burnout in the OEM compressor, the introduction of contaminants into the system during the installation process, the miswiring of the aftermarket compressor, overcharging the system with refrigerant during the installation process, or poor braze techniques when installing the aftermarket compressor.

One problem for compressors, whether an OEM compressor or an aftermarket compressor, is the entry of debris, particles or contaminants into the motor or compression mechanism, which can damage the compressor and shorten the compressor's operational life. Debris, particles or contaminants can be introduced into the system during the process of changing compressors or the contaminants, debris or particles can already be within the system from the prior failure of a compressor.

Thus, what is needed is a suction filter for a compressor that can stop contaminants, debris or particles from entering the motor or compression mechanism.

SUMMARY

The present invention is directed to a compressor including a shell having an enclosed space, a compression mechanism positioned within the enclosed space of the shell and a motor positioned within the enclosed space of the shell and connected to the compression mechanism by a shaft to power the compression mechanism. The compressor also includes a motor cap positioned on the motor opposite the compression mechanism. The motor cap includes a top surface and a sidewall extending from the top surface toward the motor. The top surface and sidewall define a plenum between the motor and the motor cap to store refrigerant. The motor cap includes at least one opening to provide passage of refrigerant between the enclosed space and the plenum. The compressor also includes a filter mechanism positioned over the at least one opening.

The present invention is also directed to a compressor including a shell having an enclosed space, a compression mechanism positioned within the enclosed space of the shell, a motor positioned within the enclosed space of the shell and connected to the compression mechanism by a shaft to power the compression mechanism. The compressor also includes a suction fitting mounted within the shell to provide for passage of refrigerant into the enclosed space. The suction fitting includes a screen positioned within the suction fitting and a cover positioned on the end of the suction fitting located within the compressor. The cover includes a plurality of louvers to direct the refrigerant flow into the enclosed space.

In the present application, a suction fitting can include screens, filters, and direction control louvers to both filter out particulates and direct higher mass liquid refrigerant downward away from the inlet to the compression chamber.

One advantage of the present application is that the suction fitting can flare or expand from a tube sized diameter to a larger diameter to allow contaminants to be trapped and still retain appropriate clean suction flow area through the suction fitting.

Another advantage of the present application is that the suction fitting can be welded into the compressor shell from the inside as a subassembly similar to that employed in the assembly of the electrical terminal.

Other features and advantages of the present application will be apparent from the following more detailed description of the embodiments, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of a hermetic compressor.

FIG. 2 schematically shows an embodiment of a vapor compression system.

FIG. 3 schematically shows another embodiment of a vapor compression system.

FIG. 4 shows an embodiment of a suction fitting mounted in a compressor shell.

FIG. 5 shows a perspective view of an embodiment of a suction fitting.

FIG. 6 shows a cross-sectional view of the suction fitting of FIG. 5.

FIG. 7 shows a front view of an exemplary of a suction fitting.

FIG. 8 shows a cross-sectional view taken along line A-A of the suction fitting of FIG. 7.

FIG. 9 shows a top view of the housing of the suction fitting of FIG. 7.

FIG. 10 shows a front view of the housing of the suction fitting of FIG. 7.

FIG. 11 shows a cross-sectional view taken along line D-D of the housing of FIG. 10.

FIG. 12 shows a cross-sectional view taken along line B-B of the housing of FIG. 10.

FIG. 13 shows a front view of an embodiment of a cover for a suction fitting.

FIG. 14 shows a cross-sectional view taken along line E-E of the cover of FIG. 13.

FIG. 15 shows a cross-sectional view taken along line F-F of the cover of FIG. 13.

FIG. 16 shows an embodiment of a screen for a suction fitting.

FIG. 17 shows an exploded view of an embodiment of a suction fitting.

FIG. 18 shows a rear perspective view of an embodiment of a suction filter for a motor cap.

FIG. 19 shows a top view of an embodiment of a suction filter for a motor cap.

FIG. 20 shows a cross-sectional view taken along line G-G of the motor cap of FIG. 19.

FIG. 21 shows a top view of an embodiment of a suction filter.

FIG. 22 shows a cross-sectional view taken along line K-K of the suction filter of FIG. 21.

FIG. 23 shows the motor cap of FIG. 19 without the suction filter.

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows an embodiment of a reciprocating compressor. However, in other embodiments, the compressor can be any suitable type of hermetic or semi-hermetic compressor including, but not limited to, a rotary compressor, screw compressor, swag link compressor, scroll compressor, spool compressor, centrifugal compressor, or turbine compressor.

In FIG. 1, compressor 2 can have a suction port or fitting 14 that can be in fluid communication with an evaporator of a vapor compression system upon the connection of a suction line or conduit from the evaporator to the suction port 14. The suction port 14 can be in fluid communication with a suction plenum 12 through one or more openings in a motor cap 13. Refrigerant gas from the evaporator can enter the compressor 2 through the suction port 14 and then flow to the suction plenum 12 before being compressed. In one embodiment, the refrigerant gas from the suction port 14 can also fill the interior space of the compressor housing before flowing to the suction plenum 12.

The compressor 2 can use an electrical motor 18. As shown in FIG. 1, motor 18 is an induction motor having a stator 20 and a rotor 22. However, in other embodiments, any other suitable type of electrical motor may be used including, but not limited to, a switched reluctance (SR) motor or an electronically commutated permanent magnet motor (ECM). A shaft assembly 24 extends through the rotor 22. The bottom end 26 of the shaft assembly 24 extends into an oil sump 405 and includes a series of apertures 27. Connected to the shaft assembly 24 below the motor is a compression device 30, such as a piston assembly as shown in FIG. 1. In FIG. 1, the piston assembly 30 has two pistons. A connecting rod 32 is connected to a piston head 34, which moves back and forth within a cylinder 36. The cylinder 36 includes a gas inlet port 38 and a gas discharge port 40. Associated with these ports 38, 40 are associated suction valves and discharge valves. The gas inlet port 38 is connected to an intake tube 54, which is in fluid communication with the suction plenum 12.

The motor 18 can be activated by a signal in response to the satisfaction of a predetermined condition, for example, an electrical signal from a thermostat when a preset temperature threshold is reached. While a thermostat is used as an example, it should be known that any type of device or signal may be used to activate the compressor. When the compressor is activated, electricity is supplied to the stator 20, and the windings in the stator 20 cause the rotor 22 to rotate. Rotation of the rotor 22 causes the shaft assembly 24 to turn. When the shaft assembly 24 is turning, oil sump fluid in the oil sump 405 enters the apertures 27 in the bottom end 26 of the shaft and then moves upward through and along the shaft 24 to lubricate the moving parts of the compressor 2.

Rotation of the rotor 22 also causes reciprocating motion of the piston assembly 30. As the assembly 30 moves to an intake position, the piston head 34 moves away from gas inlet port 38, the suction valve opens and refrigerant fluid is introduced into an expanding cylinder 36 volume. The gas is pulled from the suction plenum 12 through the intake tube 54 to the gas inlet port 38 where the gas passes through the suction valve and is introduced into the cylinder 36. When the piston assembly 30 reaches a first end (or top) of its stroke, shown by movement of the piston head 34 to the right side of the cylinder 36 of FIG. 1, the suction valve closes. The piston head 34 then compresses the refrigerant gas by reducing the cylinder 36 volume. When the piston assembly 30 moves to a second end (or bottom) of its stroke, shown by movement of piston head 34 to the left side of cylinder 36 of FIG. 1, a discharge valve is opened and the compressed refrigerant gas is expelled through the gas discharge port 40. The compressed refrigerant gas flows from the gas discharge port 40 into a muffler 50 then through an exhaust or discharge tube 52 to a discharge port or fitting. The discharge port can be in fluid communication with a condenser upon the connection of a discharge line or conduit from the condenser to the discharge port.

The compressor 2 may be connected to a vapor compression system that is included in a heating, ventilation and air conditioning (HVAC) system, refrigeration system, chilled liquid system or other suitable type of system. FIGS. 2 and 3 show different embodiments of vapor compression systems. In FIG. 2, vapor compression system 300 includes the compressor 2, a condenser 304, and an evaporator 306, while in FIG. 3, vapor compression system 300 includes the compressor 2, a reversing valve 350, an indoor unit 354 and an outdoor unit 352.

The vapor compression system 300 can be operated as an air conditioning system, where the evaporator 306 is located inside a structure or indoors, i.e., the evaporator is part of indoor unit 354, to provide cooling to the air in the structure and the condenser 304 is located outside a structure or outdoors, i.e., the condenser is part of outdoor unit 352, to discharge heat to the outdoor air. The vapor compression system 300 can also be operated as a heat pump system, i.e., a system that can provide both heating and cooling to the air in the structure, with the inclusion of the reversing valve 350 to control and direct the flow of refrigerant from the compressor 2. When the heat pump system is operated in an air conditioning mode, the reversing valve 350 is controlled to provide for refrigerant flow as described above for an air conditioning system. However, when the heat pump system is operated in a heating mode, the reversing valve 350 is controlled to provide for the flow of refrigerant in the opposite direction from the air conditioning mode. When operating in the heating mode, the condenser 304 is located inside a structure or indoors, i.e., the condenser is part of indoor unit 354, to provide heating to the air in the structure and the evaporator 306 is located outside a structure or outdoors, i.e., the evaporator is part of outdoor unit 352, to absorb heat from the outdoor air.

In vapor compression system 300, whether operated as a heat pump or as an air conditioner, the compressor 2 is driven by the motor 18 that is powered by a motor drive 104. The motor drive 104 receives AC power having a particular fixed line voltage and fixed line frequency from AC power source 102 and provides power to the motor 18. In another embodiment, the motor 18 can be powered directly from the AC power source 102. The motor 18 used in the system 300 can be any suitable type of motor that can be powered by a motor drive 104.

Referring back to FIGS. 2 and 3, the compressor 2 compresses a refrigerant vapor and delivers the vapor to the condenser 304 through a discharge line (and the reversing valve 350 if configured as a heat pump). Some examples of refrigerants that may be used in vapor compression system 300 are: hydrofluorocarbon (HFC) based refrigerants, for example, R-410A, R-407C, R-404A, R-134a and R-32 (a component of R410A and R407C); hydrofluoro olefin (HFO) refrigerants, also known as “unsaturated HFCs,” such as R1234yf; inorganic refrigerants like ammonia (NH3), R-717 and carbon dioxide (CO2), R-744; hydrocarbon (HC) based refrigerants such as propane (R-290), isobutane (R-600a) or propene (R-1270), or any other suitable type of refrigerant. The refrigerant vapor delivered by the compressor 2 to the condenser 304 enters into a heat exchange relationship with a process fluid, e.g., air or water, and undergoes a phase change to a refrigerant liquid as a result of the heat exchange relationship with the process fluid. The condensed liquid refrigerant from the condenser 304 flows through an expansion device to the evaporator 306.

The condensed liquid refrigerant delivered to the evaporator 306 enters into a heat exchange relationship with another process fluid, e.g., air or water, and undergoes a phase change to a refrigerant vapor as a result of the heat exchange relationship with the process fluid. The vapor refrigerant in the evaporator 306 exits the evaporator 306 and returns to the compressor 2 by a suction line (and the reversing valve arrangement 350 if configured as a heat pump) to complete the cycle. In other embodiments, any suitable configuration of the condenser 304 and the evaporator 306 can be used in the system 300, provided that the appropriate phase change of the refrigerant in the condenser 304 and evaporator 306 is obtained. For example, if air is used as the process fluid to exchange heat with the refrigerant in the condenser 304 or the evaporator 306, then one or more fans can be used to provide the necessary airflow through the condenser 304 or evaporator 306. The motors for the one or more fans may be powered directly from the AC power source 102 or a motor drive, such as motor drive 104.

FIG. 4 shows an embodiment of a suction fitting for a compressor. A suction fitting 80 can be mounted, fastened or installed in the shell or housing 98 of the compressor 2 by brazing or welding techniques to maintain a hermetic environment within the compressor shell 98. However, any suitable technique, e.g., epoxy, adhesives, compression fit, etc., to fasten the suction fitting 80 to the shell 98 can be used so long as the hermetic environment within the compressor is maintained. The refrigerant fluid can pass through a first portion 82 of the suction fitting 80 that is substantially cylindrical and then enter into a second portion or expansion area 84 of the suction fitting 80 that has an expanding or increasing diameter from the first portion 82. The refrigerant flow then enters the compressor shell 98 after passing through a screen 88 which can filter out and remove and debris or contaminants from the refrigerant flow and one or more louvers 86 which permit refrigerant gas to travel to the motor cap 13 and the interior of the compressor 2. The louvers 86 can also direct liquids, such as refrigerant liquid or oil, to the compressor sump 405 at the bottom of the compressor 2.

FIGS. 5-17 show different views of different embodiments of a suction fitting for a compressor. The suction fitting 80 can include three main components: a housing 83; a screen 88; and a cover 85. The housing 83 is mounted in the shell 98 of the compressor 2 and can include a first portion 82 that has a diameter that permits a tube from a system such as a heating, ventilation, and air conditioning (HVAC) or refrigeration system to be connected to the suction fitting 80. The housing 83 can have a second portion 84 of expanding diameter that is connected to a cylindrical third portion 87 that is located opposite the first portion 82.

The second portion 84 of the housing 83 can be at a predetermined angle A (see FIG. 12) relative to the first portion 82 of the housing 83. In one embodiment, the predetermined angle can range between about 90 degrees and about 135 degrees and can be 125 degrees. In another embodiment, the diameter of the third portion 87 can be about 2 to 4 times greater than the diameter of the first portion 82. In one embodiment, an end 89 of the third portion 87 can have an undulating, wavy or curved surface with high points and low points (see FIG. 9, 11, 12 or 17). In other words, the axial length of the third portion 87 can vary along the circumference of the third portion 87 between a minimum axial length corresponding to a low point and a maximum axial length corresponding to a high point. In another embodiment, the end 89 of the third portion 87 can have a substantially planar surface and the axial length of the third portion can be the same along the circumference of the third portion 87

The housing 83 can include fastening mechanisms 91, 93 that receive screws or other fastening devices 92, 94 to hold the screen 88 and cover 85 in place. In one embodiment, the fastening devices 92, 94 can be placed at a predetermined angle B (see FIG. 10) between adjacent fastening devices 92, 94. The fastening mechanisms 91 can be integral with the third portion 87 of the housing 83 to receive the screws or fastening devices 92 used to attach the cover 85 to the housing 83. The fastening mechanisms 93 can be integral with the second portion 84 of the housing 83 to receive the screws or fastening devices 94 used to attach the screen or filter 88 to the housing 83. In other embodiments, the fastening mechanisms 91, 93 can be attached to the housing 83 using any suitable technique such as welding or adhesives.

A screen or filter 88 can be placed inside the housing 83 and mounted to the housing 83 at the end of the second portion 84 having the larger diameter using fastening devices 94 and fastening mechanisms 93. The screen 88 can be a substantially circular piece of metal with one or more apertures 103 (see FIG. 16) to receive fastening devices 94 that can then be inserted into fastening mechanisms 93 in the housing 83. In addition, the screen 88 can have one or more cutouts 105 (see FIG. 16) to help hold the screen 88 in position and to permit the screen 88 to be installed in the housing 83 without interfering with the fastening mechanisms 91 receiving the fastening devices 92 for the cover 85. In one embodiment, the screen 88 can be positioned at the junction of the second portion 84 and the third portion 87 and have a diameter C (see FIG. 16) that corresponds to the inside diameter of the second portion 84. The screen 88 can have holes 107 (see FIG. 16) that have a diameter that can be between about 0.01 inches and about 0.05 inches and can be 0.03 inches. The holes 107 can be positioned or arranged in the sheet 88 in a generally circular area having a diameter D (see FIG. 16) that is less than diameter C such that a border area is provided around the sheet 88 for improved stability and rigidity. The size and position of the holes 107 can be selected to capture debris and contaminants in the refrigerant flow while still permitting flow through the screen 88. In other embodiments, the screen 88 can be connected or mounted to the housing 83 by any suitable technique such as welding, adhesive or compression fit. In still other embodiments, the screen 88 can be a stainless steel wire mesh having a mesh size of between 50×50 and 100×100 and a wire diameter between 0.0045 inches and 0.009 inches.

A cover 85 with louvers 86 can be positioned and mounted on the end 89 and outer surface of the third portion 87 of the housing 83. The cover 83 can have integral louvers 86 that can be used to coalesce any entrained liquids in the flow through the suction fitting 80. The louvers can be arranged within a circular outline 113 (see FIG. 13). The louvers 86 can be angled such that the coalesced liquids then drain to the oil sump 405 in the bottom of the compressor 2. The cover 85 can have a portion 109 that extends over the third portion 87 of the housing 83. In addition, the cover 85 can have one or more openings 111 that can receive fastening devices 92 that mate with corresponding fastening mechanisms 91 in the housing 83. In one embodiment, the cover 85 can have a curved shape to mate with the undulating or curved end surface 89 of the third portion 87. In another embodiment, the cover 85 can be mounted within the housing 83 instead of outside of the housing 83. In still other embodiments the cover 85 can be connected to the housing 83 by any suitable technique such as welding, adhesive or compression fit.

In another embodiment, instead of using the suction fitting 80 to filter debris and contaminants from the refrigerant flow, a suction filter can be placed over (or in front of) the openings in the motor cap to prevent debris or contaminants from entering the motor or the compression mechanism.

FIGS. 18-23 show different views of a motor cap and suction filter for the motor cap. The motor cap 13 can have holes 200 positioned on approximately 25-75% of the top surface 202 of the motor cap 13. In other embodiments, the holes 200 can be positioned over a greater or lesser percentage of the top surface 202 of the motor cap 13 so long as an appropriate amount of refrigerant enters the suction plenum 12.

In one embodiment, the motor cap 13 can have a first portion 204 and a second portion 206. The holes 200 can be positioned or located on the second portion 206 of the motor cap 13. A minor axis 210 of the motor cap 13 through a center point 212 of the depression 95 can be used as a divider between the first portion 204 and the second portion 206. However, any suitable location or configuration for the divider between the first portion 204 and the second portion 206 can be used.

The holes 200 can be arranged in a patterned configuration where the distances between holes 200 and the locations of the holes 200 are consistent, i.e., the same predetermined distance(s) and location placement(s) are used in the configuration. In another embodiment, the holes 200 can have a more random configuration where the distances between holes 200 and the locations of the holes 200 are not consistent, i.e., multiple predetermined distances and location placements can be used in a non-structured manner. In one embodiment, the holes 200 can be arranged in the shape of an arc, square, rectangle, triangle, circle, oval, trapezoid or any other suitable geometric shape. In addition, the holes 200 can be arranged using one or more geometric shapes, either symmetrically or asymmetrically placed about a major axis 214 of the motor cap 13 through the center point 212 of the depression 95. The number of holes 200 in the top surface 202 of the motor cap 13 can vary between 2 holes and 200 or more holes depending on the size of the motor cap 13 and the diameter of the holes 200.

The holes 200 can be arranged in a patterned configuration having a plurality of rows and columns. In the embodiments of FIGS. 12-15, the rows and columns can be arranged such that the holes 200 in one row or column are offset the holes 200 in the adjacent or neighboring rows or columns by 60 degrees (see e.g., FIG. 12). In other embodiments, the offset angle between holes in adjacent rows or columns can be greater than or less than 60 degrees depending on the number and size of holes 200. The number of holes 200 in a row or column can vary between 1 hole and 20 or more holes.

As shown in FIG. 23, the predetermined spacing between holes in the same row or column is shown by dimension B and the predetermined spacing between holes in adjacent rows or columns in shown by dimension A. In one embodiment, dimension B can range between about 2.25 inches and about 2.65 inches and can be 2.45 inches and dimension A can range between about 0.50 inches and 1.00 inches and can be 0.75 inches.

In one embodiment, the holes 200 can have a circular shape. However, in other embodiments, the holes 200 can use one or more suitable geometric shapes including, but not limited to, square, rectangle, triangle, circle, oval, hexagon and octagon. The holes 200 can use a constant predetermined diameter or size, i.e., each hole 200 has the same diameter or size. However, in another embodiment, the holes 200 can have different predetermined diameters or sizes that can be arranged in particular configurations to obtain particular characteristics such as improved flow, noise control, etc. The diameter(s) for the holes 200 shown in FIGS. 23 can range between about 1.00 inches and about 1.50 inches and can be 1.25 inches.

A filtering device 250 can be placed over the holes 200 in the motor cap 13 to prevent any debris or contaminants from entering the suction plenum 12 (and possibly the motor 18 or compression device 30). The filtering device 250 can have a mesh 252 connected or fastened to a border or flange 254. In one embodiment, the mesh 252 can be a stainless steel wire mesh having a mesh size of between 50×50 and 100×100 and a wire diameter between 0.0045 inches and 0.009 inches. The border or flange 254 can provide stability and rigidity to the mesh 252 and also provides an area for the filtering device 250 to be connected to the top surface 202 of the motor cap 13. The filtering device 250 can be attached to the top surface 202 of the motor cap 13 by any suitable technique such as welding, adhesive or fasteners. The filtering device 250 can have shape that corresponds to the pattern of the holes 200 in the motor cap 13 and provides for the passage of refrigerant through both the mesh 252 and holes 200. In other words, the filtering mechanism 250 has a shape that does not completely block any holes 200.

In another embodiment, the motor cap 13 can have a single hole 200 in either to the top surface 202 or a sidewall of the motor cap 13 to receive refrigerant and the filtering mechanism 250 can be placed directly over the single hole 200 to filter debris and contaminants.

The motor cap 13 can also include numerous other features needed for the installation of the motor cap 13 and the operation of the compressor 2. For example, the motor cap 12 can include openings 224 (see FIG. 18) for electrical connections. In addition, the motor cap 13 can include the depression or indentation 95 to receive a spring or other stabilizing device 96 to hold the motor 18 and compression mechanism 30 in position in the compressor shell 98 and to prevent vibrations in the shell or housing 98 from being transferred to the motor 18 and compression mechanism.

As would be appreciated by those of ordinary skill in the pertinent art, the functions of several elements of the present application may, in alternative embodiments, be carried out by fewer elements, or a single element. Similarly, in some embodiments, any functional element may perform fewer, or different, operations than those described with respect to the exemplary embodiment. Also, functional elements shown as distinct in the drawings may be incorporated within other functional elements, separated in different hardware or distributed in various ways in a particular implementation. Further, relative size and location are merely somewhat schematic and it is understood that not only the same but many other embodiments could have varying depictions.

All relative descriptions herein such as above, below, left, right, up, and down are with reference to the Figures, and not meant in a limiting sense. Relative descriptions such as inner and inward are with reference to being a direction toward the interior of a compressor shell whereas outer and outward are a direction away from the compressor. The shown assemblies can be understood as providing exemplary features of varying detail of certain embodiments, and therefore, components, modules, elements, and/or aspects of the drawings can be otherwise added to, combined, interconnected, sequenced, separated, interchanged, positioned, and/or rearranged without materially departing from the disclosed systems or methods. Additionally, the shapes and sizes of components are also exemplary and unless otherwise specified, can be altered without materially affecting or limiting the disclosed technology.

It is important to note that the construction and arrangement of the present application as shown in the various exemplary embodiments is demonstrative only. Although only a few embodiments have been described in detail in this application, those who review this application can readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described in the application. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present application. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present application. Accordingly, the present application is not limited to a particular embodiment, but extends to various modifications that nevertheless fall within the scope of the appended claims.

Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the invention, or those unrelated to enabling the invention). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation. 

What is claimed is:
 1. A compressor comprising: a shell having an enclosed space; a compression mechanism positioned within the enclosed space of the shell; a motor positioned within the enclosed space of the shell and connected to the compression mechanism by a shaft to power the compression mechanism; a motor cap positioned on the motor opposite the compression mechanism, the motor cap comprising a top surface and a sidewall extending from the top surface toward the motor, the top surface and sidewall defining a plenum between the motor and the motor cap to store refrigerant; the motor cap comprising at least one opening to provide passage of refrigerant between the enclosed space and the plenum; and a filter mechanism positioned over the at least one opening.
 2. The compressor of claim 1 wherein the at least one opening is positioned in the top surface of the motor cap.
 3. The compressor of claim 2 wherein the at least one opening comprises a plurality of openings.
 4. A compressor comprising: a shell having an enclosed space; a compression mechanism positioned within the enclosed space of the shell; a motor positioned within the enclosed space of the shell and connected to the compression mechanism by a shaft to power the compression mechanism; a suction fitting mounted within the shell to provide for passage of refrigerant into the enclosed space, the suction fitting comprising: a screen positioned within the suction fitting; and a cover positioned on the end of the suction fitting located within the compressor, the cover comprising a plurality of louvers to direct the refrigerant flow into the enclosed space. 